Don Quixote is a Spanish novel by Miguel de Cervantes. It was originally published in two parts, in 1605 and 1615. Considered a founding work of Western literature, it is often labelled as the first modern novel and the greatest work ever written. Don Quixote is also one of the most-translated books in the world and one of the best-selling novels of all time.

The plot revolves around the adventures of a member of the lowest nobility, an hidalgo[d] from La Mancha named Alonso Quijano, who reads so many chivalric romances that he loses his mind and decides to become a knight-errant (caballero andante) to revive chivalry and serve his nation, under the name Don Quixote de la Mancha.

The book had a major influence on the literary community, as evidenced by direct references in Alexandre Dumas's The Three Musketeers (1844), and Edmond Rostand's Cyrano de Bergerac (1897) as well as the word quixotic. Mark Twain referred to the book as having "swept the world's admiration for the mediaeval chivalry-silliness out of existence".